org.eclipse.gmf.runtime.emf.core/src/org/eclipse/gmf/runtime/emf/core/util/EMFCoreUtil.java - gmf-runtime/org.eclipse.gmf-runtime - Git at Google

 /******************************************************************************
  * Copyright (c) 2006, 2010 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/epl-v10.html
  *
  * Contributors:
  *    IBM Corporation - initial API and implementation
  ****************************************************************************/

 package org.eclipse.gmf.runtime.emf.core.util;

 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Iterator;
 import java.util.List;

 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.EAnnotation;
 import org.eclipse.emf.ecore.EAttribute;
 import org.eclipse.emf.ecore.EClass;
 import org.eclipse.emf.ecore.ENamedElement;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EReference;
 import org.eclipse.emf.ecore.EStructuralFeature;
 import org.eclipse.emf.ecore.InternalEObject;
 import org.eclipse.emf.ecore.EStructuralFeature.Setting;
 import org.eclipse.emf.ecore.resource.Resource;
 import org.eclipse.emf.ecore.resource.ResourceSet;
 import org.eclipse.emf.ecore.resource.Resource.Factory.Registry;
 import org.eclipse.emf.ecore.util.EcoreUtil;
 import org.eclipse.emf.ecore.util.FeatureMapUtil;
 import org.eclipse.emf.ecore.xmi.XMLResource;
 import org.eclipse.emf.transaction.TransactionalEditingDomain;
 import org.eclipse.emf.transaction.util.TransactionUtil;
 import org.eclipse.gmf.runtime.common.core.util.Trace;
 import org.eclipse.gmf.runtime.emf.core.internal.plugin.EMFCoreDebugOptions;
 import org.eclipse.gmf.runtime.emf.core.internal.plugin.EMFCorePlugin;
 import org.eclipse.gmf.runtime.emf.core.internal.util.EMFCoreConstants;
 import org.eclipse.gmf.runtime.emf.core.resources.IExtendedResourceFactory;
 import org.eclipse.gmf.runtime.emf.core.resources.IResourceHelper;


 /**
  * Static utilities for working with EMF objects and resources in the GMF
  * environment.
  *
  * @author Christian W. Damus (cdamus)
  */
 public class EMFCoreUtil {

 	/**
 	 * Creates an object at a given containment reference whose
 	 * <code>EClass</code> is eClass.
 	 *
 	 * @param container
 	 *            The container of the new object.
 	 * @param reference
 	 *            The feature containing the object.
 	 * @param eClass
 	 *            The <code>EClass</code>.
 	 * @return The new <code>EObject</code>.
 	 */
 	public static EObject create(EObject container, EReference reference,
 			EClass eClass) {

 		EObject result = null;

 		IResourceHelper helper = Util.getHelper(container.eResource());

 		if (helper != null) {

 			result = helper.create(eClass);

 		} else {
 			result = eClass.getEPackage().getEFactoryInstance().create(eClass);
 		}

 		if (FeatureMapUtil.isMany(container,reference)) {
 			((Collection) container.eGet(reference)).add(result);
 		} else {
 			container.eSet(reference, result);
 		}

 		return result;
 	}

 	/**
 	 * Gets the first container with the specified EClass.
 	 *
 	 * @param eObject
 	 *            The <code>EObject</code>.
 	 * @param eClass
 	 *            The eClass.
 	 * @return The container.
 	 */
 	public static EObject getContainer(EObject eObject, EClass eClass) {

 		for (EObject parent = eObject; parent != null; parent = parent
 			.eContainer())
 			if (eClass.isInstance(parent))
 				return parent;

 		return null;
 	}

 	/**
 	 * Finds the first common container of a collection of objects.
 	 *
 	 * @param objects
 	 *            The <code>EObject</code>s.
 	 * @param desiredContainerType
 	 *            The desired <code>EClass</code> of the container.
 	 * @return The least common container.
 	 */
 	public static EObject getLeastCommonContainer(Collection objects,
 			EClass desiredContainerType) {

 		EObject commonContainer = null;

 		List prevContainers = new ArrayList();

 		Iterator i = objects.iterator();

 		while (i.hasNext()) {

 			EObject element = (EObject) i.next();
 			List containers = new ArrayList();

 			boolean found = false;

 			EObject container = element;

 			while (container != null) {

 				EClass containerClass = container.eClass();

 				if ((desiredContainerType == containerClass)
 					|| (desiredContainerType.isSuperTypeOf(containerClass))) {

 					containers.add(container);

 					if (!found) {

 						if ((prevContainers.isEmpty())
 							|| (commonContainer == null)) {
 							commonContainer = container;
 							found = true;

 						} else if ((prevContainers.contains(container))
 							&& (EcoreUtil.isAncestor(container, commonContainer))) {

 							commonContainer = container;
 							found = true;
 						}
 					}
 				}

 				container = container.eContainer();
 			}

 			if (!found)
 				return null;

 			prevContainers = containers;
 		}

 		return commonContainer;
 	}

 	/**
 	 * Uses a reverse reference map that is maintained by the MSL service to
 	 * find all referencers of a particular element. The search can be narrowed
 	 * down by passing the list of Reference features to match.
 	 * <code>features</code> can be null.
 	 *
 	 * @param eObject
 	 *            The referenced object.
 	 * @param features
 	 *            The reference features.
 	 * @return The collection of referencers.
 	 */
 	public static Collection getReferencers(EObject eObject,
 			EReference[] features) {

 		CrossReferenceAdapter crossReferenceAdapter =
 				CrossReferenceAdapter.getExistingCrossReferenceAdapter(eObject);

 		if (crossReferenceAdapter == null) {
 			TransactionalEditingDomain domain = TransactionUtil.getEditingDomain(
 				eObject);

 			if (domain != null) {
 				crossReferenceAdapter = CrossReferenceAdapter.getCrossReferenceAdapter(
 					domain.getResourceSet());
 			}

 			if (crossReferenceAdapter == null) {
 				// still null?  Give up
 				return Collections.EMPTY_LIST;
 			}
 		}

 		Collection settings  = crossReferenceAdapter.getInverseReferences(eObject);

 		if (settings.isEmpty() == false) {
 			ArrayList referencers = new ArrayList();
 			int count;
 			if ((features != null) && ((count = features.length) != 0)) {
 				Iterator it = settings.iterator();
 				while (it.hasNext()) {
 					Setting setting = (Setting) it.next();
 					EStructuralFeature feature = setting
 					.getEStructuralFeature();
 					for(int i = 0; i< count;++i){
 						if (feature == features[i]) {
 							referencers.add(setting.getEObject());
 							break;
 						}
 					}
 				}
 			} else {
 				Iterator it = settings.iterator();
 				while (it.hasNext()) {
 					referencers.add(((Setting) it.next()).getEObject());
 				}
 			}
 			return referencers;
 		}
 		return Collections.EMPTY_LIST;
 	}

 	/**
 	 * Gets the imports of a resource.  These are the resources to which this
 	 * <code>resource</code> has references.
 	 *
 	 * @param resource a resource.
 	 * @return the imports of the resource
 	 */
 	public static Collection getImports(Resource resource) {
 		TransactionalEditingDomain domain = TransactionUtil.getEditingDomain(resource);

 		if (domain != null) {
 			return CrossReferenceAdapter.getCrossReferenceAdapter(domain.getResourceSet()).getImports(resource);
 		}

 		return Collections.EMPTY_SET;
 	}

 	/**
 	 * Gets the exports of a resource.  These are the resources that have
 	 * references to the <code>resource</code>.
 	 *
 	 * @param resource a resource.
 	 * @return the exports of the resource
 	 */
 	public static Collection getExports(Resource resource) {
 		TransactionalEditingDomain domain = TransactionUtil.getEditingDomain(resource);

 		if (domain != null) {
 			return CrossReferenceAdapter.getCrossReferenceAdapter(domain.getResourceSet()).getExports(resource);
 		}

 		return Collections.EMPTY_SET;
 	}

 	/**
 	 * Gets the transitive closure of the imports of a resource.  This obtains
 	 * those resources that import the <code>resource</code>, the resources
 	 * that import those, etc.
 	 *
 	 * @param resource a resource.
 	 * @return the transitive imports of the resource
 	 */
 	public static Collection getTransitiveImports(Resource resource) {
 		Collection result = new HashSet();
 		Collection unload = new HashSet();

 		getTransitiveImports(resource, result, unload);

 		for (Iterator i = unload.iterator(); i.hasNext();) {
 			((Resource) i.next()).unload();
 		}

 		return result;
 	}

 	/**
 	 * Helper method to recursively compute transitive imports of a resource.
 	 */
 	private static void getTransitiveImports(Resource resource, Collection imports,
 			Collection unload) {

 		if (!resource.isLoaded()) {

 			try {
 				resource.load(Collections.EMPTY_MAP);
 			} catch (Exception e) {
 				// ignore resources that fail to load.
 			}

 			unload.add(resource);
 		}

 		Collection directImports = getImports(resource);

 		for (Iterator i = directImports.iterator(); i.hasNext();) {

 			Resource directImport = (Resource) i.next();

 			if (!imports.contains(directImport)) {

 				imports.add(directImport);

 				getTransitiveImports(directImport, imports, unload);
 			}
 		}
 	}

 	/**
 	 * Gets the transitive closure of the exports of a resource.  This obtains
 	 * those resources that export the <code>resource</code>, the resources
 	 * that export those, etc.
 	 *
 	 * @param resource a resource.
 	 * @return the transitive exports of the resource
 	 */
 	public static Collection getTransitiveExports(Resource resource) {
 		Collection result = new HashSet();
 		Collection unload = new HashSet();

 		getTransitiveExports(resource, result, unload);

 		for (Iterator i = unload.iterator(); i.hasNext();) {
 			((Resource) i.next()).unload();
 		}

 		return result;
 	}

 	/**
 	 * Helper method to recursively compute transitive imports of a resource.
 	 */
 	private static void getTransitiveExports(Resource resource, Collection exports,
 			Collection unload) {

 		if (!resource.isLoaded()) {

 			try {
 				resource.load(Collections.EMPTY_MAP);
 			} catch (Exception e) {
 				// ignore resources that fail to load.
 			}

 			unload.add(resource);
 		}

 		Collection directExports = getExports(resource);

 		for (Iterator i = directExports.iterator(); i.hasNext();) {

 			Resource directExport = (Resource) i.next();

 			if (!exports.contains(directExport)) {

 				exports.add(directExport);

 				getTransitiveExports(directExport, exports, unload);
 			}
 		}
 	}

 	/**
 	 * Gets the name of an object if the object has name, returns an empty
 	 * string otherwise.
 	 *
 	 * @param eObject
 	 *            The object.
 	 * @return The object's name.
 	 */
 	public static String getName(EObject eObject) {

 		if (eObject == null) {
 			return EMFCoreConstants.EMPTY_STRING;
 		}

 		if (eObject.eIsProxy())
 			return getProxyName(eObject);

 		EAttribute nameAttribute = PackageUtil.getNameAttribute(eObject
 			.eClass());

 		if (nameAttribute != null) {

 			String name = (String) eObject.eGet(nameAttribute);

 			if (name != null)
 				return name;
 		}

 		return EMFCoreConstants.EMPTY_STRING;
 	}

 	private static String getProxyName(EObject proxy) {

 		URI uri = EcoreUtil.getURI(proxy);
         Resource.Factory factory = null;

         ResourceSet rs = null;
         Resource r = proxy.eResource();
         if (r != null)
             rs = r.getResourceSet();
         if (rs != null)
             factory = rs.getResourceFactoryRegistry().getFactory(uri);
         if (factory == null)
             factory = Resource.Factory.Registry.INSTANCE
                 .getFactory(uri);

 		String result = null;

 		if (factory instanceof IExtendedResourceFactory) {
 			result = ((IExtendedResourceFactory) factory).getProxyName(proxy);
 		}

 		if (result == null) {
 			// default algorithm

 			result = EMFCoreConstants.EMPTY_STRING;
 		}

 		return result;
 	}

 	/**
 	 * Sets the name of an object if the object can be assigned a name.
 	 *
 	 * @param eObject
 	 *            The object.
 	 * @param name
 	 *            The object's new name.
 	 *
 	 * @throws IllegalArgumentException if the <code>eObject</code> does not
 	 *     have a name attribute
 	 */
 	public static void setName(EObject eObject, String name) {

 		EAttribute nameAttribute = PackageUtil.getNameAttribute(eObject
 			.eClass());

 		if (nameAttribute != null) {

 			eObject.eSet(nameAttribute, name);

 		} else {

 			RuntimeException e = new IllegalArgumentException(
 				"object has no name attribute"); //$NON-NLS-1$

 			Trace.throwing(EMFCorePlugin.getDefault(),
 				EMFCoreDebugOptions.EXCEPTIONS_THROWING, EMFCoreUtil.class,
 				"setName", e); //$NON-NLS-1$

 			throw e;
 		}
 	}

 	/**
 	 * Gets the fully qualified name of an object.
 	 *
 	 * @param eObject
 	 *            The object.
 	 * @param formatted
 	 *            if True, unnamed parents will be listed using their meta-class
 	 *            name.
 	 * @return The object's qualified name.
 	 */
 	public static String getQualifiedName(EObject eObject, boolean formatted) {

 		if (eObject.eIsProxy())
 			return getProxyQualifiedName(eObject);

 		if (!formatted) {

 			EAttribute qNameAttribute = PackageUtil.getQualifiedNameAttribute(
 				eObject.eClass());

 			if (qNameAttribute != null) {

 				String qualifiedName = (String) eObject.eGet(qNameAttribute);

 				if (qualifiedName != null)
 					return qualifiedName;
 				else
 					return EMFCoreConstants.EMPTY_STRING;
 			}
 		}

 		String prefix = EMFCoreConstants.EMPTY_STRING;

 		EObject eContainer = eObject.eContainer();

 		while ((eContainer != null) && (eContainer instanceof EAnnotation))
 			eContainer = eContainer.eContainer();

 		if (eContainer != null)
 			prefix = getQualifiedName(eContainer, formatted);

 		String name = getName(eObject);

 		if ((formatted) && (name.equals(EMFCoreConstants.EMPTY_STRING)))
 			name = EMFCoreConstants.META_CLASS_BEGIN
 				+ PackageUtil.getLocalizedName(eObject.eClass())
 				+ EMFCoreConstants.META_CLASS_END;

 		return (prefix.length() == 0) ? name
 			: (prefix + ((name.equals(EMFCoreConstants.EMPTY_STRING)) ? EMFCoreConstants.EMPTY_STRING
 				: (EMFCoreConstants.QUALIFIED_NAME_SEPARATOR + name)));
 	}

 	private static String getProxyQualifiedName(EObject proxy) {

 		URI uri = EcoreUtil.getURI(proxy);

 		Resource.Factory factory = Resource.Factory.Registry.INSTANCE
 			.getFactory(uri);

 		String result = null;

 		if (factory instanceof IExtendedResourceFactory) {
 			result = ((IExtendedResourceFactory) factory).getProxyQualifiedName(proxy);
 		}

 		if (result == null) {
 			// default algorithm

 			result = EMFCoreConstants.EMPTY_STRING;
 		}

 		return result;
 	}

 	/**
 	 * Gets the proxy ID by parsing the proxy URI.
 	 *
 	 * @param proxy
 	 *            The proxy object.
 	 * @return The ID.
 	 */
 	public static String getProxyID(EObject proxy) {

 		if (proxy == null) {
 			return EMFCoreConstants.EMPTY_STRING;
 		}

 		if (!proxy.eIsProxy() && (proxy.eResource() instanceof XMLResource)) {
 			XMLResource res = (XMLResource) proxy.eResource();

 			if (res == null) {
 				return EMFCoreConstants.EMPTY_STRING;
 			} else {
                 String id =  res.getID(proxy);
                 // if the object had no ID then the best we can do is to return the URI Fragment
                 if (id ==null || id.length() ==0){
                     return res.getURIFragment(proxy);
                 }
             }
 		}

 		Resource.Factory factory = null;

 		URI uri = EcoreUtil.getURI(proxy);

 		if (uri != null) {
 			Resource resource = proxy.eResource();

 			if (resource != null) {
 				ResourceSet resourceSet = resource.getResourceSet();

 				if (resourceSet != null) {
 					Registry registry = resourceSet.getResourceFactoryRegistry();

 					if (registry != null) {
 						factory = registry.getFactory(uri);
 					}
 				}
 			}

 			if (factory == null) {
 				factory = Resource.Factory.Registry.INSTANCE.getFactory(uri);
 			}
 		}

 		String result = null;

 		if (factory instanceof IExtendedResourceFactory) {
 			result = ((IExtendedResourceFactory) factory).getProxyID(proxy);
 		}

 		if (result == null) {
 			// default implementation

 			result = Util.getProxyID(proxy);
 		}

 		return result;
 	}

 	/**
 	 * Gets the proxy class by parsing the proxy URI.
 	 *
 	 * @param proxy
 	 *            The proxy object.
 	 * @return The class.
 	 */
 	public static EClass getProxyClass(EObject proxy) {

 		if (proxy == null) {
 			return null;
 		}

 		if (!proxy.eIsProxy()) {
 			return proxy.eClass();
 		}

 		URI uri = EcoreUtil.getURI(proxy);

 		Resource.Factory factory = Resource.Factory.Registry.INSTANCE
 			.getFactory(uri);

 		String id = null;

 		if (factory instanceof IExtendedResourceFactory) {
 			id = ((IExtendedResourceFactory) factory).getProxyClassID(proxy);
 		}

 		if (id == null) {
 			// default algorithm

 			id = PackageUtil.getID(proxy.eClass());
 		}

 		if (id != null) {

 			ENamedElement element = PackageUtil.getElement(id);

 			if ((element != null) && (element instanceof EClass))
 				return (EClass) element;
 		}

 		return null;
 	}

 	/**
 	 * Creates a proxy of the specified type with the specified proxy URI.
 	 *
 	 * @param classID
 	 *            The type of proxy to create.
 	 * @param uri
 	 *            The URI for the new proxy.
 	 * @return The new proxy.
 	 */
 	public static EObject createProxy(EClass eClass, URI uri) {
 		InternalEObject proxy = (InternalEObject) eClass.getEPackage()
 			.getEFactoryInstance().create(eClass);
 		proxy.eSetProxyURI(uri);

 		return proxy;
 	}

 	/**
 	 * Attempts to resolve the specified <code>proxy</code> object, returning
 	 * <code>null</code> (rather than the original proxy) if it is unresolvable.
 	 *
 	 * @param domain
 	 *            Th editing domain.
 	 * @param proxy
 	 *            The proxy object.
 	 * @return The resolved object, or <code>null</code> if not resolved
 	 */
 	public static EObject resolve(TransactionalEditingDomain domain,
 			EObject proxy) {

 		if (proxy == null)
 			return null;

 		if (!proxy.eIsProxy())
 			return proxy;

 		URI uri = EcoreUtil.getURI(proxy);

 		Resource.Factory factory = Resource.Factory.Registry.INSTANCE
 			.getFactory(uri);

 		if (factory instanceof IExtendedResourceFactory) {
 			return ((IExtendedResourceFactory) factory).resolve(domain, proxy);
 		}

 		// the default algorithm

 		return Util.resolve(domain, proxy);
 	}
 }
	/******************************************************************************
	* Copyright (c) 2006, 2010 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/epl-v10.html
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	****************************************************************************/

	package org.eclipse.gmf.runtime.emf.core.util;

	import java.util.ArrayList;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.HashSet;
	import java.util.Iterator;
	import java.util.List;

	import org.eclipse.emf.common.util.URI;
	import org.eclipse.emf.ecore.EAnnotation;
	import org.eclipse.emf.ecore.EAttribute;
	import org.eclipse.emf.ecore.EClass;
	import org.eclipse.emf.ecore.ENamedElement;
	import org.eclipse.emf.ecore.EObject;
	import org.eclipse.emf.ecore.EReference;
	import org.eclipse.emf.ecore.EStructuralFeature;
	import org.eclipse.emf.ecore.InternalEObject;
	import org.eclipse.emf.ecore.EStructuralFeature.Setting;
	import org.eclipse.emf.ecore.resource.Resource;
	import org.eclipse.emf.ecore.resource.ResourceSet;
	import org.eclipse.emf.ecore.resource.Resource.Factory.Registry;
	import org.eclipse.emf.ecore.util.EcoreUtil;
	import org.eclipse.emf.ecore.util.FeatureMapUtil;
	import org.eclipse.emf.ecore.xmi.XMLResource;
	import org.eclipse.emf.transaction.TransactionalEditingDomain;
	import org.eclipse.emf.transaction.util.TransactionUtil;
	import org.eclipse.gmf.runtime.common.core.util.Trace;
	import org.eclipse.gmf.runtime.emf.core.internal.plugin.EMFCoreDebugOptions;
	import org.eclipse.gmf.runtime.emf.core.internal.plugin.EMFCorePlugin;
	import org.eclipse.gmf.runtime.emf.core.internal.util.EMFCoreConstants;
	import org.eclipse.gmf.runtime.emf.core.resources.IExtendedResourceFactory;
	import org.eclipse.gmf.runtime.emf.core.resources.IResourceHelper;


	/**
	* Static utilities for working with EMF objects and resources in the GMF
	* environment.
	*
	* @author Christian W. Damus (cdamus)
	*/
	public class EMFCoreUtil {

	/**
	* Creates an object at a given containment reference whose
	* <code>EClass</code> is eClass.
	*
	* @param container
	* The container of the new object.
	* @param reference
	* The feature containing the object.
	* @param eClass
	* The <code>EClass</code>.
	* @return The new <code>EObject</code>.
	*/
	public static EObject create(EObject container, EReference reference,
	EClass eClass) {

	EObject result = null;

	IResourceHelper helper = Util.getHelper(container.eResource());

	if (helper != null) {

	result = helper.create(eClass);

	} else {
	result = eClass.getEPackage().getEFactoryInstance().create(eClass);
	}

	if (FeatureMapUtil.isMany(container,reference)) {
	((Collection) container.eGet(reference)).add(result);
	} else {
	container.eSet(reference, result);
	}

	return result;
	}

	/**
	* Gets the first container with the specified EClass.
	*
	* @param eObject
	* The <code>EObject</code>.
	* @param eClass
	* The eClass.
	* @return The container.
	*/
	public static EObject getContainer(EObject eObject, EClass eClass) {

	for (EObject parent = eObject; parent != null; parent = parent
	.eContainer())
	if (eClass.isInstance(parent))
	return parent;

	return null;
	}

	/**
	* Finds the first common container of a collection of objects.
	*
	* @param objects
	* The <code>EObject</code>s.
	* @param desiredContainerType
	* The desired <code>EClass</code> of the container.
	* @return The least common container.
	*/
	public static EObject getLeastCommonContainer(Collection objects,
	EClass desiredContainerType) {

	EObject commonContainer = null;

	List prevContainers = new ArrayList();

	Iterator i = objects.iterator();

	while (i.hasNext()) {

	EObject element = (EObject) i.next();
	List containers = new ArrayList();

	boolean found = false;

	EObject container = element;

	while (container != null) {

	EClass containerClass = container.eClass();

	if ((desiredContainerType == containerClass)
	\|\| (desiredContainerType.isSuperTypeOf(containerClass))) {

	containers.add(container);

	if (!found) {

	if ((prevContainers.isEmpty())
	\|\| (commonContainer == null)) {
	commonContainer = container;
	found = true;

	} else if ((prevContainers.contains(container))
	&& (EcoreUtil.isAncestor(container, commonContainer))) {

	commonContainer = container;
	found = true;
	}
	}
	}

	container = container.eContainer();
	}

	if (!found)
	return null;

	prevContainers = containers;
	}

	return commonContainer;
	}

	/**
	* Uses a reverse reference map that is maintained by the MSL service to
	* find all referencers of a particular element. The search can be narrowed
	* down by passing the list of Reference features to match.
	* <code>features</code> can be null.
	*
	* @param eObject
	* The referenced object.
	* @param features
	* The reference features.
	* @return The collection of referencers.
	*/
	public static Collection getReferencers(EObject eObject,
	EReference[] features) {

	CrossReferenceAdapter crossReferenceAdapter =
	CrossReferenceAdapter.getExistingCrossReferenceAdapter(eObject);

	if (crossReferenceAdapter == null) {
	TransactionalEditingDomain domain = TransactionUtil.getEditingDomain(
	eObject);

	if (domain != null) {
	crossReferenceAdapter = CrossReferenceAdapter.getCrossReferenceAdapter(
	domain.getResourceSet());
	}

	if (crossReferenceAdapter == null) {
	// still null? Give up
	return Collections.EMPTY_LIST;
	}
	}

	Collection settings = crossReferenceAdapter.getInverseReferences(eObject);

	if (settings.isEmpty() == false) {
	ArrayList referencers = new ArrayList();
	int count;
	if ((features != null) && ((count = features.length) != 0)) {
	Iterator it = settings.iterator();
	while (it.hasNext()) {
	Setting setting = (Setting) it.next();
	EStructuralFeature feature = setting
	.getEStructuralFeature();
	for(int i = 0; i< count;++i){
	if (feature == features[i]) {
	referencers.add(setting.getEObject());
	break;
	}
	}
	}
	} else {
	Iterator it = settings.iterator();
	while (it.hasNext()) {
	referencers.add(((Setting) it.next()).getEObject());
	}
	}
	return referencers;
	}
	return Collections.EMPTY_LIST;
	}

	/**
	* Gets the imports of a resource. These are the resources to which this
	* <code>resource</code> has references.
	*
	* @param resource a resource.
	* @return the imports of the resource
	*/
	public static Collection getImports(Resource resource) {
	TransactionalEditingDomain domain = TransactionUtil.getEditingDomain(resource);

	if (domain != null) {
	return CrossReferenceAdapter.getCrossReferenceAdapter(domain.getResourceSet()).getImports(resource);
	}

	return Collections.EMPTY_SET;
	}

	/**
	* Gets the exports of a resource. These are the resources that have
	* references to the <code>resource</code>.
	*
	* @param resource a resource.
	* @return the exports of the resource
	*/
	public static Collection getExports(Resource resource) {
	TransactionalEditingDomain domain = TransactionUtil.getEditingDomain(resource);

	if (domain != null) {
	return CrossReferenceAdapter.getCrossReferenceAdapter(domain.getResourceSet()).getExports(resource);
	}

	return Collections.EMPTY_SET;
	}

	/**
	* Gets the transitive closure of the imports of a resource. This obtains
	* those resources that import the <code>resource</code>, the resources
	* that import those, etc.
	*
	* @param resource a resource.
	* @return the transitive imports of the resource
	*/
	public static Collection getTransitiveImports(Resource resource) {
	Collection result = new HashSet();
	Collection unload = new HashSet();

	getTransitiveImports(resource, result, unload);

	for (Iterator i = unload.iterator(); i.hasNext();) {
	((Resource) i.next()).unload();
	}

	return result;
	}

	/**
	* Helper method to recursively compute transitive imports of a resource.
	*/
	private static void getTransitiveImports(Resource resource, Collection imports,
	Collection unload) {

	if (!resource.isLoaded()) {

	try {
	resource.load(Collections.EMPTY_MAP);
	} catch (Exception e) {
	// ignore resources that fail to load.
	}

	unload.add(resource);
	}

	Collection directImports = getImports(resource);

	for (Iterator i = directImports.iterator(); i.hasNext();) {

	Resource directImport = (Resource) i.next();

	if (!imports.contains(directImport)) {

	imports.add(directImport);

	getTransitiveImports(directImport, imports, unload);
	}
	}
	}

	/**
	* Gets the transitive closure of the exports of a resource. This obtains
	* those resources that export the <code>resource</code>, the resources
	* that export those, etc.
	*
	* @param resource a resource.
	* @return the transitive exports of the resource
	*/
	public static Collection getTransitiveExports(Resource resource) {
	Collection result = new HashSet();
	Collection unload = new HashSet();

	getTransitiveExports(resource, result, unload);

	for (Iterator i = unload.iterator(); i.hasNext();) {
	((Resource) i.next()).unload();
	}

	return result;
	}

	/**
	* Helper method to recursively compute transitive imports of a resource.
	*/
	private static void getTransitiveExports(Resource resource, Collection exports,
	Collection unload) {

	if (!resource.isLoaded()) {

	try {
	resource.load(Collections.EMPTY_MAP);
	} catch (Exception e) {
	// ignore resources that fail to load.
	}

	unload.add(resource);
	}

	Collection directExports = getExports(resource);

	for (Iterator i = directExports.iterator(); i.hasNext();) {

	Resource directExport = (Resource) i.next();

	if (!exports.contains(directExport)) {

	exports.add(directExport);

	getTransitiveExports(directExport, exports, unload);
	}
	}
	}

	/**
	* Gets the name of an object if the object has name, returns an empty
	* string otherwise.
	*
	* @param eObject
	* The object.
	* @return The object's name.
	*/
	public static String getName(EObject eObject) {

	if (eObject == null) {
	return EMFCoreConstants.EMPTY_STRING;
	}

	if (eObject.eIsProxy())
	return getProxyName(eObject);

	EAttribute nameAttribute = PackageUtil.getNameAttribute(eObject
	.eClass());

	if (nameAttribute != null) {

	String name = (String) eObject.eGet(nameAttribute);

	if (name != null)
	return name;
	}

	return EMFCoreConstants.EMPTY_STRING;
	}

	private static String getProxyName(EObject proxy) {

	URI uri = EcoreUtil.getURI(proxy);
	Resource.Factory factory = null;

	ResourceSet rs = null;
	Resource r = proxy.eResource();
	if (r != null)
	rs = r.getResourceSet();
	if (rs != null)
	factory = rs.getResourceFactoryRegistry().getFactory(uri);
	if (factory == null)
	factory = Resource.Factory.Registry.INSTANCE
	.getFactory(uri);

	String result = null;

	if (factory instanceof IExtendedResourceFactory) {
	result = ((IExtendedResourceFactory) factory).getProxyName(proxy);
	}

	if (result == null) {
	// default algorithm

	result = EMFCoreConstants.EMPTY_STRING;
	}

	return result;
	}

	/**
	* Sets the name of an object if the object can be assigned a name.
	*
	* @param eObject
	* The object.
	* @param name
	* The object's new name.
	*
	* @throws IllegalArgumentException if the <code>eObject</code> does not
	* have a name attribute
	*/
	public static void setName(EObject eObject, String name) {

	EAttribute nameAttribute = PackageUtil.getNameAttribute(eObject
	.eClass());

	if (nameAttribute != null) {

	eObject.eSet(nameAttribute, name);

	} else {

	RuntimeException e = new IllegalArgumentException(
	"object has no name attribute"); //$NON-NLS-1$

	Trace.throwing(EMFCorePlugin.getDefault(),
	EMFCoreDebugOptions.EXCEPTIONS_THROWING, EMFCoreUtil.class,
	"setName", e); //$NON-NLS-1$

	throw e;
	}
	}

	/**
	* Gets the fully qualified name of an object.
	*
	* @param eObject
	* The object.
	* @param formatted
	* if True, unnamed parents will be listed using their meta-class
	* name.
	* @return The object's qualified name.
	*/
	public static String getQualifiedName(EObject eObject, boolean formatted) {

	if (eObject.eIsProxy())
	return getProxyQualifiedName(eObject);

	if (!formatted) {

	EAttribute qNameAttribute = PackageUtil.getQualifiedNameAttribute(
	eObject.eClass());

	if (qNameAttribute != null) {

	String qualifiedName = (String) eObject.eGet(qNameAttribute);

	if (qualifiedName != null)
	return qualifiedName;
	else
	return EMFCoreConstants.EMPTY_STRING;
	}
	}

	String prefix = EMFCoreConstants.EMPTY_STRING;

	EObject eContainer = eObject.eContainer();

	while ((eContainer != null) && (eContainer instanceof EAnnotation))
	eContainer = eContainer.eContainer();

	if (eContainer != null)
	prefix = getQualifiedName(eContainer, formatted);

	String name = getName(eObject);

	if ((formatted) && (name.equals(EMFCoreConstants.EMPTY_STRING)))
	name = EMFCoreConstants.META_CLASS_BEGIN
	+ PackageUtil.getLocalizedName(eObject.eClass())
	+ EMFCoreConstants.META_CLASS_END;

	return (prefix.length() == 0) ? name
	: (prefix + ((name.equals(EMFCoreConstants.EMPTY_STRING)) ? EMFCoreConstants.EMPTY_STRING
	: (EMFCoreConstants.QUALIFIED_NAME_SEPARATOR + name)));
	}

	private static String getProxyQualifiedName(EObject proxy) {

	URI uri = EcoreUtil.getURI(proxy);

	Resource.Factory factory = Resource.Factory.Registry.INSTANCE
	.getFactory(uri);

	String result = null;

	if (factory instanceof IExtendedResourceFactory) {
	result = ((IExtendedResourceFactory) factory).getProxyQualifiedName(proxy);
	}

	if (result == null) {
	// default algorithm

	result = EMFCoreConstants.EMPTY_STRING;
	}

	return result;
	}

	/**
	* Gets the proxy ID by parsing the proxy URI.
	*
	* @param proxy
	* The proxy object.
	* @return The ID.
	*/
	public static String getProxyID(EObject proxy) {

	if (proxy == null) {
	return EMFCoreConstants.EMPTY_STRING;
	}

	if (!proxy.eIsProxy() && (proxy.eResource() instanceof XMLResource)) {
	XMLResource res = (XMLResource) proxy.eResource();

	if (res == null) {
	return EMFCoreConstants.EMPTY_STRING;
	} else {
	String id = res.getID(proxy);
	// if the object had no ID then the best we can do is to return the URI Fragment
	if (id ==null \|\| id.length() ==0){
	return res.getURIFragment(proxy);
	}
	}
	}

	Resource.Factory factory = null;

	URI uri = EcoreUtil.getURI(proxy);

	if (uri != null) {
	Resource resource = proxy.eResource();

	if (resource != null) {
	ResourceSet resourceSet = resource.getResourceSet();

	if (resourceSet != null) {
	Registry registry = resourceSet.getResourceFactoryRegistry();

	if (registry != null) {
	factory = registry.getFactory(uri);
	}
	}
	}

	if (factory == null) {
	factory = Resource.Factory.Registry.INSTANCE.getFactory(uri);
	}
	}

	String result = null;

	if (factory instanceof IExtendedResourceFactory) {
	result = ((IExtendedResourceFactory) factory).getProxyID(proxy);
	}

	if (result == null) {
	// default implementation

	result = Util.getProxyID(proxy);
	}

	return result;
	}

	/**
	* Gets the proxy class by parsing the proxy URI.
	*
	* @param proxy
	* The proxy object.
	* @return The class.
	*/
	public static EClass getProxyClass(EObject proxy) {

	if (proxy == null) {
	return null;
	}

	if (!proxy.eIsProxy()) {
	return proxy.eClass();
	}

	URI uri = EcoreUtil.getURI(proxy);

	Resource.Factory factory = Resource.Factory.Registry.INSTANCE
	.getFactory(uri);

	String id = null;

	if (factory instanceof IExtendedResourceFactory) {
	id = ((IExtendedResourceFactory) factory).getProxyClassID(proxy);
	}

	if (id == null) {
	// default algorithm

	id = PackageUtil.getID(proxy.eClass());
	}

	if (id != null) {

	ENamedElement element = PackageUtil.getElement(id);

	if ((element != null) && (element instanceof EClass))
	return (EClass) element;
	}

	return null;
	}

	/**
	* Creates a proxy of the specified type with the specified proxy URI.
	*
	* @param classID
	* The type of proxy to create.
	* @param uri
	* The URI for the new proxy.
	* @return The new proxy.
	*/
	public static EObject createProxy(EClass eClass, URI uri) {
	InternalEObject proxy = (InternalEObject) eClass.getEPackage()
	.getEFactoryInstance().create(eClass);
	proxy.eSetProxyURI(uri);

	return proxy;
	}

	/**
	* Attempts to resolve the specified <code>proxy</code> object, returning
	* <code>null</code> (rather than the original proxy) if it is unresolvable.
	*
	* @param domain
	* Th editing domain.
	* @param proxy
	* The proxy object.
	* @return The resolved object, or <code>null</code> if not resolved
	*/
	public static EObject resolve(TransactionalEditingDomain domain,
	EObject proxy) {

	if (proxy == null)
	return null;

	if (!proxy.eIsProxy())
	return proxy;

	URI uri = EcoreUtil.getURI(proxy);

	Resource.Factory factory = Resource.Factory.Registry.INSTANCE
	.getFactory(uri);

	if (factory instanceof IExtendedResourceFactory) {
	return ((IExtendedResourceFactory) factory).resolve(domain, proxy);
	}

	// the default algorithm

	return Util.resolve(domain, proxy);
	}
	}